check inv error only in debug mode
check inv error only in debug mode

jnishi/chainer,niboshi/chainer,keisuke-umezawa/chainer,wkentaro/chainer,ktnyt/chainer,anaruse/chainer,hvy/chainer,niboshi/chainer,tkerola/chainer,jnishi/chainer,okuta/chainer,wkentaro/chainer,hvy/chainer,niboshi/chainer,hvy/chainer,keisuke-umezawa/chainer,niboshi/chainer,chainer/chainer,jnishi/chainer,chainer/chainer,aonotas/chainer,ktnyt/chainer,wkentaro/chainer,chainer/chainer,keisuke-umezawa/chainer,wkentaro/chainer,okuta/chainer,chainer/chainer,rezoo/chainer,pfnet/chainer,ktnyt/chainer,okuta/chainer,ronekko/chainer,hvy/chainer,okuta/chainer,ktnyt/chainer,keisuke-umezawa/chainer,jnishi/chainer